Fbct-Black Bleeding

I am doing a cake this weekend that is to have a grey background and a black jumpman logo that is going to be black. The last FBCT I did was red on white. I froze the tranfer and placed on the cake the night before and then refrigerated the entire cake until the next day and took out it. There was some bleeding/sweating of the red onto the white. I'm scared the same thing will happen again. There was no filling or anything so I know the actual cake doesn't have to be refridgerated, but will the room temperature cake and the frozen transfer sweat as it comes to room temperature? Or what causes this and how can I fix it? Thanks!!